At present, motor vehicles have become necessary transportation means in daily life. Specifically, cars and motorcycles have almost been involved in every aspect of the life of the people nowadays. Today, with the increasing environment-friendly consciousness, as the fuel vehicles (consuming fuel), such as cars and motorcycles, bring about the problem of air pollution, electric vehicles with environment-friendly purpose have emerged. And various electric vehicles can be seen.
To reduce the vehicle self-weight and cost, the conventional chassis for electric vehicles, which has a differential and half-axle combination, can not meet current requirements. Consequently, an electric vehicle driven by double motors have been presented.
A double motor driving mechanism for electric vehicles disclosed in Chinese Patent No. CN200320127977.7 comprises two driving motors and two driving wheels, wherein said two driving motors are connected to the two driving wheels, respectively. Such driving means, i.e. in which double motors operate to drive individually, leaves out both the conventional rear axle combination having a differential and half-axle and the complicated mechanical driving gears, greatly decreasing the vehicle weight and cost as a whole and reducing the power loss. Also it can totally avoid the disadvantage with the conventional mechanical differential, i.e. the whole vehicle can not move forward as a result of that one wheel can not rotate while another one is wheelspining. However, when the ground is not absolutely flat, only three of the four wheels of a rigid vehicle frame are in contact with the ground. If the front wheel tilts, the steering stability will be affected. In case that a rear wheel is separated away from the ground, the driving force will be reduced. Additionally, both of the above situations seriously affect the safety and stability of vehicle driving. Accordingly, along with using the double motor for driving and reducing the total vehicle weight, it is also necessary to improve the stability and power output characteristics of electric vehicle chassis.